I had comms between the two but soon disconnected them. There was some irksome aspect that I can't quite remember, may have been 808 switching on when I'd rather it stayed off when not in use! (The 808 was at the other end of the room, beside the Master DSP and in sight of my PJ screen when watching a film)

As Bruce mentioned, the volume displays won't track together, but I didn't mind that, as the 808 (and your 818) are not running the system volume. Your G68 is doing that; volume adjustment is actually handled in the speakers, the figures you see on the processor and 818 are just the commands being sent to instruct the speaker, there's no attenuation of the digital signal.

Cheers

George